Fixed - bakkeby/dusk GitHub Wiki
Fixed is a flag that indicates that the client window is fixed in size and is therefore never to
be tiled. Ultimately this means that fixed windows are always floating and can't be toggled to be
tiled.
This flag is set internally if the size hints of the client window indicates that the maximum and minimum size are the same. In other words this means that the window can't be resized.
The flag can also be explicitly set via a client rule if the intention is that the window should always remain floating.
This will typically apply to widgets, conky, bars, etc. that have a static size.